If I calculate petrol cost into buying material from a shop and parking charges, this way is more expensive.
The problem with on line is that computer screen does not always show. Good colour . When they arrive you are disappointed. Online is also very good for specific fabric ie bugs, transport etc which small shop do not stock.
I go on line a great deal. I also buy some of the sale cheap end of bolts to use as backing fabric. A lot cheaper than £12 a metre..